1. Field of the Invention
This invention relates generally to testing apparatus for the operator-assisted testing of an electronic device under test (EDUT) and, more particularly, to a testing apparatus with an ergonomic handle assembly for EDUT loading and unloading with single operator motions.
2. Description of the Related Art
For electronic devices such as data storage tape and disk drives, performance testing is part of the usual factory quality-control process. Although many of the fabrication steps are completely automated, the quality-control testing procedures require the intervention of a human operator to transfer the electronic device under test (EDUT) from the assembly line to the testing station, to connect the various signal and power cables, to start the testing procedures and to remove the EDUT from the test station following the quality-control tests. Because the manufacturing rate and volume are very high for such electronic devices, these operator-assisted testing steps usually require rapid repetition of many stressful physical operations, which increases the incidence of repetitive-motion injuries. Intense competition among manufacturers strongly motivates the development and implementation of testing procedures that minimize unit manufacturing costs. Ergonomic operator procedures minimize operator injuries, thereby reducing overall manufacturing costs.
Moreover, in the usual practice, the test apparatus has several cables, which must be connected to and disconnected from hundreds of EDUTs each day. After tens or hundreds of thousands of load/unload cycles, the cables develop unpredictable failures, such as open-circuits, sporadic intermissions and short-circuits. Perhaps these failures are related to the cyclic mechanical bending of the cables as well as the tensile stress induced by pulling on the cable to disconnect the EDUT following testing. These sorts of failures can be very costly to the manufacturer because failing test cables can give erroneous quality control test results leading to a high rate of false-rejection and unnecessary rework. It is estimated that this situation alone costs one large data tape drive manufacturer millions of dollars per year in unneeded rework expenses.
Frequently, the forces required to manually connect and disconnect cable connectors to the EDUT are large. Sometimes the connector pins bind and disconnection forces as high as thirty pounds must be applied (in an awkward fashion) to overcome the binding forces. This disconnection force must be applied through the operator""s fingertips while grasping the connector body to avoid pulling on the cable instead of the connector body itself. Sudden disconnection under force causes sudden and uncontrolled motion by the operator""s fingers and hands, which can cause pain and soft-tissue damage, especially when repeated hundreds of times throughout the day, every day.
It is desirable to resolve this problem by providing a testing apparatus with an ergonomic means for loading (connecting) and unloading (disconnecting) an EDUT. Such an ergonomic loading/unloading apparatus must limit the operator motion required to a single low-force controlled movement for loading and a similar movement during unloading, while avoiding unwanted strain to the cables and unwanted stress on the connectors. Until now, this has not been possible because of the well-known limitations discussed above. These unresolved problems and deficiencies are clearly felt in the art and are solved by this invention in the manner described below.
It is a purpose of this invention to provide an efficient and ergonomic apparatus for use in testing electronic devices in factories where they are manufactured. This invention can be used wherever electrical signal cables must be mated to electronic circuit boards with operator-assistance.
It is an advantage of this invention that it can be used to test tape drives, disk drives, compact disk reader (CDR) drives, digital versatile disk (DVD) drives, floppy drives and circuit boards.
It is another purpose of this invention to provide a testing apparatus that avoids stressing the electronic signal cables that are connected to the EDUT. All such cables are fixed to the tester apparatus and are not bent nor stressed unless the tester apparatus is disassembled for maintenance or repair. Thus, it is an advantage of this invention that the number of cable connector stress cycles is reduced by many hundreds of thousands of times over the life of the tester apparatus by using the spring-probe assembly of this invention, which is reliable over millions of connect/disconnect cycles.
It is another purpose of this invention to provide an ergometric loader for the tester apparatus. It is an advantage of this invention that force and impact applied to the operator""s hands and wrists are dramatically decreased over the stress and impact produced with tester apparatus of the present art. In accordance with this invention, a single smooth low-force motion is sufficient to completely load the EDUT into the tester. Similarly, a smooth low-force movement in the opposite direction is sufficient to unload the EDUT completely from the tester.
It is yet another purpose of this invention to provide a modular test apparatus suitable for use as a building block for creating a multi-bay test station for the asynchronous testing of a plurality of EDUTs simultaneously. In such a multi-bay test station, the individual test modes may differ and may be run asynchronously. Spring-probe blocks of different functionality may be used in each bay.
The present invention provides an ergonomic-testing apparatus for operator-assisted testing of an electronic device under test (EDUT) removably loaded in the apparatus. A translatable carriage is movably mounted on a fixture frame for removably supporting the EDUT during loading and testing. A spring-probe block connector assembly is mounted on the fixture frame to engage a mating connector in the EDUT. An ergonomic loading assembly is movably engaged to the fixture frame and operatively engaged with the translatable carriage and is movable in loading and unloading directions to engage and disengage the EDUT with the spring-probe block connector assembly.
In one aspect of our invention, the foregoing basic combination is combined with an enclosed chassis that supports the fixture frame which is in monolithic form, one or more tester circuit cards and a connector to a remote computer.
In another aspect of our invention, the basic combination includes a chassis that supports the fixture frame and a power-margin circuit board mounted to the chassis and coupled to the spring-probe block connector assembly for producing a plurality of predetermined combinations of power-supply voltage levels to the EDUT.
In still another aspect of our invention, the basic combination includes a mating connector in the EDUT that allows the exchange of optical data, and the spring-probe block connector assembly includes a connector that makes an optical data connection with the mating connector in the EDUT.
In still another aspect of our invention, the basic combination includes a first infrared signal transceiver in the EDUT and a second infrared signal transceiver fixed to a chassis that supports the fixture frame for exchanging signals with the EDUT.
In still another aspect of our invention, the basic combination includes a multiplexer circuit board connected to the spring-probe block connector assembly to facilitate selection between a plurality of different connections to the EDUT.
In still another aspect of our invention, the basic combination includes a chassis that supports the fixture frame and one or more tester circuit cards mounted in the chassis for generating a plurality of electronic signals for use in creating a plurality of predetermined test conditions for the EDUT and an EDUT tester cable coupled to the spring-probe block connector assembly for transferring electronic signals.
In still another aspect of our invention, the basic combination includes a compensator circuit fixed to the spring-probe block connector assembly for selecting one of a plurality of EDUT mating connectors and for matching circuit impedances between an EDUT tester cable and the one EDUT mating connector.
In a final aspect of our invention, the basic combination includes a chassis and a plurality of compliant supports that connect the fixture frame to the chassis.
The foregoing, together with other features and advantages of this invention, can be better appreciated with reference to the following specification, claims and the accompanying drawing.